But in the meantime, if they are not such a gamechanger, then why make obstacles to possess them then?
Because jackass, the government will restrict any weapon it can, any time it can, to any extent it can, and this behavior scales infinitely, as you'd know if you'd observed the weapon laws of Europe over the last fifty years, or you knew anything about weapon laws in the US. Nothing has any "justification" besides "what can we get away with today". Short barreled shotguns as the government defines them in its bans have never been used by insurgents or soldiers anywhere, ever, yet they're banned. They're banned but the Serbu Shorty isn't despite being a shotgun you can fit in a fucking lunchbox.
the government will ban a SPECIFIC BULLET from being used for hunting a SPECIFIC ANIMAL if you let them, for no other reason than to make it slightly more difficult for gun owners and the gun market.